title: Mapping the charged residues in the second immunoglobulin-like domain of the vascular endothelial growth factor/placenta growth factor receptor Flt-1 required for binding and structural stability.
abstract: Flt-1 is one of two receptor tyrosine kinases through which the angiogenic factor vascular endothelial growth factor (VEGF) functions. Placenta growth factor (PlGF) is an additional ligand for Flt-1. The second immunoglobulin-like domain in the extracellular domain of Flt-1 has previously been identified as the region containing the critical ligand-binding determinants. We analyzed the contribution of charged residues within the first three domains of Flt-1 to ligand binding by alanine-scanning mutagenesis. Domain 2 residues Arg159, Glu208 and His223-Arg224 (together) affect both VEGF and PlGF binding, while Glu137, Lys171, His223, and Arg224 affect PlGF but not VEGF. Several charged residues, especially Asp187, are important in maintaining the structural integrity of domain 2. In addition, some residues in domain 3 contribute to binding (Asp231) or provide for additional discrimination between ligands (Arg280-Asp283).
authors.affiliation: Departments of Cardiovascular Research, Genentech, Inc., South San Francisco, California 94080, USA.
authors.forename: T
authors.initials: T
authors.lastname: Davis-Smyth
authors.forename: L G
authors.initials: LG
authors.lastname: Presta
authors.forename: N
authors.initials: N
authors.lastname: Ferrara
mesh_terms: D000409:Alanine / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D016228:Endothelial Growth Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007136:Immunoglobulins / Q000737:chemistry* / Q000378:metabolism; D008222:Lymphokines / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D042461:Vascular Endothelial Growth Factor A; D040281:Vascular Endothelial Growth Factor Receptor-1; D042442:Vascular Endothelial Growth Factors
chemical_list: D016228:Endothelial Growth Factors; D007136:Immunoglobulins; D008222:Lymphokines; D011518:Proto-Oncogene Proteins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D020794:Receptor Protein-Tyrosine Kinases; D040281:Vascular Endothelial Growth Factor Receptor-1; D000409:Alanine